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I love your concept, photographing surfaces and making them into computer wallpaper. What interests me most is how people react to different surfaces tactilly, emotionally, and intellectually. In addition to Rusty's perceptive comments and analysis, here are some additional thoughts to consider about your stone wall photo:
1.) Your lighting is flat and therefore the photo tends to be one dimensional. If you compare this to the dramatic lighting in the Zion photo, the bright sunlight enhances the warm, earthy colors and textures that are so eye catching. Perhaps photographing the stone wall with more expressive lighting will make the stones more 3 dimensional.
2.) The Zion photo has patterns and interest areas that the viewer can grab onto. With the stone wall photo showing such a large section of wall, the viewer has a harder time finding a place for their eye to land and little direction how the eye should move through the photo. Like Rusty has suggested, try a smaller section.
3.) The cold, gray surface of the stone wall can be naturally off putting, as compared to the warm, earthy feeling you've created in the Zion photo. You may need to find an "irritant" like a plant growing out of the wall, or some interesting eye catching flaw, that will "center" the composition like what the pebbles do in the Zion photo. One thought is to photograph the stone wall after a rain storm or snow storm to heighten the texture, color, drama.
Here's an example of a smaller section.